US 11,822,443 B2Granted

Highly-available distributed network address translation (NAT) architecture with failover solutions

AssigneeCisco Technology, Inc.

InventorsPierre Pfister, Ian James Wells, Kyle Andrew Donald Mestery, William Mark Townsley, Yoann Desmouceaux, Guillaume Ruty, Aloys Augustin

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Abstract

This disclosure describes techniques for providing a distributed scalable architecture for Network Address Translation (NAT) systems with high availability and mitigations for flow breakage during failover events. The NAT servers may include functionality to serve as fast-path servers and/or slow-path servers. A fast-path server may include a NAT worker that includes a cache of NAT mappings to perform stateful network address translation and to forward packets with minimal latency. A slow-path server may include a mapping server that creates new NAT mappings, depreciates old ones, and answers NAT worker state requests. The NAT system may use virtual mapping servers (VMSs) running on primary physical servers with state duplicated VMSs on different physical failover servers. Additionally, the NAT servers may implement failover solutions for dynamically allocated routeable address/port pairs assigned to new sessions by assigning new outbound address/port pairs when a session starts and broadcasting pairing information.

Claims20

Dependent claims

A system comprising:

one or more processors;
and
one or more non-transitory computer-readable media storing computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to:
configure a plurality of virtual mapping servers (VMSs) to operate on a cluster of physical servers, an individual VMS of the plurality of VMSs is associated with a primary physical server and a failover physical server, and the cluster of physical servers includes a first physical server and a second physical server;
configure a primary first VMS to run on the first physical server;
configure a failover first VMS to run on the second physical server, the failover first VMS being a duplicate image of the primary first VMS;
generate a network address translation (NAT) mapping for the plurality of VMSs;
receive an indication of server failure for the first physical server;
cause the failover first VMS on the second physical server to behave as the primary first VMS;
regenerate the NAT mapping based at least in part on the indication of server failure, wherein regenerating the NAT mapping includes indicating the failover first VMS as the primary first VMS;
configure a second failover first VMS to run on a third physical server of the cluster of physical servers, the second failover first VMS being the duplicate image of the primary first VMS;
determine a state change on the primary first VMS;
and
determine to copy the state change to the second failover first VMS.

11 more elements

One or more non-transitory computer readable media storing computer-executable instructions that, when executed, cause one or more processors to perform operations comprising:

generating a network address translation (NAT) mapping for a plurality of virtual mapping servers (VMSs) to a cluster of physical servers, an individual VMS of the plurality of VMSs is associated with a primary physical server and a failover physical server and is associated with a pool of non-overlapping public addresses and ports;
configuring a primary first VMS to run on a first physical server of the cluster of physical servers;
configuring a failover first VMS to run on a second physical server of the cluster of physical servers, the failover first VMS being a duplicate image of the primary first VMS;
receiving an indication of server failure for the first physical server;
causing the failover first VMS on the second physical server to behave as the primary first VMS;
identifying a failover second VMS on the first physical server based at least in part on the NAT mapping;
identifying a primary second VMS associated with the failover second VMS based at least in part on the NAT mapping;
and
configuring a second failover second VMS to run on a third physical server of the cluster of physical servers, the second failover second VMS being a second duplicate image of the primary second VMS.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/902,677Filed 2 Sep 2022 · continuation
Priority: 3 Oct 2019
Published: US 2022/0413975 A129 Dec 2022
Granted: 21 Nov 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

G06F 11/2033
Failover techniques: switching over of hardware resources
H04L 61/2532
Translation architectures other than single NAT servers: clique of NAT servers
G06F 9/45558
Hypervisors; Virtual machine monitors: hypervisor-specific management and integration aspects
G06F 11/2023
Where processing functionality is redundant: failover techniques

Family

Application16/592,613Parent of this continuation · filed 3 Oct 2019
US 11,436,111 B2Parent of this continuation · filed 6 Sep 2022
US 2022/0413975 A1Pre-grant publication · published 29 Dec 2022
US 2021/0103507 A1Published application
US 11,822,443 B2This patent

From the US filing history. Foreign family members aren’t listed.